the science behind the beauty

pH products: lemon juice

You’ve most likely heard of using lemon juice in my beauty recipes as an easy DIY activity. Just from Pinterest alone, I’ve seen user reviews of people saying that lemon juice helps brighten skin, works great as a toner and can even help fade acne scars. Sounds great right?

Recently a friend was telling me about her turmeric face mask, in which she mixed honey, turmeric powder, and lemon juice. The scientist in me immediately wondered if the lemon juice was actually helpful or if the low pH could damage her skin. So for this week’s pH products I’m investigating whether this popular DIY ingredient is helping or harming our skin.

Lemon juice definitely has a place in cosmetics. Lemon juice itself has approximately 5% citric acid and is a great source of vitamin C (ascorbic acid). Many lemon-derived ingredients can be found in beauty products, but is adding pure lemon juice for a DIY recipe good for our skin’s pH mantel?

After using litmus paper to test the pH of lemon juice from a freshly cut lemon I was shocked to find that lemon juice has a pH of ~2! That is extremely low considering our skin has a pH of about ~5.5. The acid in lemons makes this ingredient very harmful towards our skin.

Overall I’d say to stay away from DIY recipes involving a lot of lemon juice. Adding a few drops, such as the face mask I mentioned earlier, shouldn’t do much harm especially if it’s a rinse off. However using lemon juice as a toner or skin brightener can cause pigmentation and skin irritation problems. Stick to using beauty products on the market that are formulated with lemon derived ingredients if you really want to add some lemon juice to your beauty routine.